Grammatical comprehension in language and communication disorders.

Autism Spectrum Disorder (ASD) and Developmental Language Disorder (DLD) have traditionally been considered separate disorders, although some similarities and overlaps in certain aspects of language have been detected. In this paper, we compare the deficits in receptive grammar in these two disorders. We analyse the proportion of grammatical errors in relation to semantic complexity in 84 children divided into four groups: children with autism language impairment (ALI), with autism language normal (ALN), with DLD, and with typical development (TD), all groups with the same age of receptive vocabulary. The results show significant differences in the comprehension of grammatical structures, both simple (canonical and non-reversible) and complex (non-canonical and reversible). Children with ASD and DLD show different language profiles depending on the syntactic complexity. In the simplest structures, no differences are found between the groups, starting at an equivalent vocabulary age of 7:8 years. However, there are differences between the ALI and DLD groups with respect to the TD group in the more complex structures, starting at an equivalent vocabulary age of 3 years. Therefore, both groups ALI and DLD present the greatest difficulties compared to ALN and TD. The paper discusses the importance of attending to these differences, since the repercussion of comprehension difficulties increases as children grow.